Removable check unit



April 9, 1963 F. s. FLICK ETAL 3,084,709

REMOVABLE CHECK UNIT Filed May 19, 1960 FIELl United dtates @arent 3,084,709 REMOVABLE CHECK UNIT Francis S. Flick, Oak Park, and Walter Il. Kutllaty, Elmburst, lll., assignors to Flick-Reedy Corporation, a corporation of Illinois Filed May 19, 1960, Ser. No. 30,108 2 Claims. (Cl. 137-4545) This invention relates to a piston and cylinder device, and more particularly to a fluid ow controller which, when operatively related to an air operated piston and cylinder device, allows the piston and cylinder device to be used as a cushioning member, even if the air supply is accidentally interrupted.

In the operation of die cutting and die stamping presses and the like, air cylinders have Ibeen used to cushion the movement of heavy die members. Precaution -must be taken to see that the air cylinders yfunction when the air supply is accidentally interrupted; otherwise costly damage may result to the heavy die members. While check valves and the like, located on air supply lines might be used to insure safety and continuous operation of the piston and cylinder device, in the event that the air supply was interrupted, this use of check valves is costly, the check Valves may be easily tampered with, and it is time consuming to disconnect and reposition them in the event of necessary piping changes. The greatest -difliculty with this arrangement has been that workmen, in changing the position of the cylinder or piping connections, or in dismantling a part of the equipment for repairs, have forgot-ten to replace the check valves, or have damaged them, and unknowingly would leave the system without a safety device.

The present invention provides an economical and simple method Ifor achieving continuous operation lfor a time, of a piston and cylinder device used as a cushioning member, even if the air supply is accidentally interrupted. This invention is constructed so that it traps air on the intake side of the cylinder and enables the piston and cylinder device to continue to function for a period of time, during which time the die equipment can be safely operated prior to shut down. The invention is placed within the piston and cylinder device in such a manner that little maintenance is required, there is very little likelihood of tampering, and there is no need to remove it while maintenance is being performed on equipment or on the air supply line.

vIt is the primary object of this invention to provide a new and improved uid tlow controller .for a piston and cylinder device.

Another object of this invention is to provide a novel structure allowing continuous operation of the piston and cylinder device as a cushioning member even though the air supply is accidentally interrupted.

A further object of this iluid flow controller is to provide normal operation of a piston and cylinder device without interference from external check valve controls and the like, and to provide a controller that requires little maintenance, and in which there -is very little likelihood of tampering `due to its novel construction and placement within the piston ,and cylinder device.

Another object is to provide a fluid ilow controller that is of simple design and that is easy and economical to manufacture.

`Other objects, features and advantages of the invention will be apparent `from the following descrip-tion of a preferred embodiment, illustrated in the accompanying drawing, in Iwhich:

IFIG. l is a longitudinal sectional view through the center line of the piston and cylinder device having the invention mounted in each of the -iluid ports to illustrate its location relative to the piston and cylinder device;

FIG 2 is a fragmentary enlarged sectional view through the center line of the liuid flow controller of this invention as mounted in the exhaust port illustrated in FIG. 1;

IEIG. 3 is a fragmentary enlarged sectional view through the center of the iiuid flow controller of this invention as mounted in the intake port illustrated in FIG. 1;

FIG. 4 shows the top plan view of the fluid ow controller embodying the invention;

FIG. 5 shows the bottom plan view of the iluid flow controller illustrated in FIG. 4;

lFIG. 6 shows a plan view of the valve member removed -from the controller, and

FIG. 7 shows an alternate torm of the valve member in plan.

The particular iluid llo/w controllers chosen for illustration are shown in conjunction with a piston and cylinder device which preferably has a motive lluid of pneumatic natu-re. The particular piston and cylinder device illustrated in lFlG. l has a cylindrical barrel 7, a cap 8 at one end, a head 9 at the other end with a retainer plate 10 abutting thereagainst to hold a piston rod bushing 11 in place. The head and cap are held onto the cylinder barrel by tie rods extending -through the cap 8 and head 9 and having exposed nuts 12.

A piston assembly 13 is mounted upon a piston rod 14 which extends through the bushing 11 and the en d of the piston rod is connected in a manner to move witha die member (not shown). The particular piston illustrated is equipped with a cushion plunger A15 which may enter into a fluid port opening 16 fformcd within the cap 8, the port having a portion providing communication laterally through a passage 17 to an air supply line 18. Fluid port Ztl has a portion providing communication laterally through a passage 21 in which is connected an exhaust line 22. `Other features of the piston and cylinder device illustrated do not have particular applicability to the invention which is concerned only with the fluid flow controller. These -features are illustrated to explain the environment in which the fluid ow controller in its preferred form is to be used.

ln normal practice, in the operation of a piston and cylinder device used as a cushioning member, an air supply line 1S is connected to the intake port 17 and an exhaust line 22 is connected to the exhaust port 21. The outer portion of the tluid ports 17 and 21 are provided with pipe Ithreads 25 and 26. The present invention may also be used with a straight lthreaded port having a sufficient length of thread to receive the connecting lines and the iluid flow controller. The outer portion or pipe threads 25 which are fully formed or perfect threads, provides a connection `for air intake line 18. The inner imperfect portion of threads 25, those partially formed and therefore impenfectf provides a mounting space for the iluid flow controller 23. The outer or perfect portion of threads 26 provides a connection for air `exhaust line 22. The inner or imperfec portion of threads 26 provides a connection `for -uid ow controller 24. 'Ihe fluid ilow controllers 23 and 2-4 are positioned within ponts 17 and 21 so that they do not interfere with the lines 18 and 22.

FIGS. 2 and 3 illustrate the particular structure of the fluid ilow controller. FIG. Z illustrates the iluid ow controller 24 in position in the exhaust port 21. FIG. 3 illustrates the uid llow controller 23 in position in the intake port 17. The same structure of the fluid ilow controller is used in opposite ports, but in port 2.1 fluid llow controller, 24 is shown in the inverted position. In FIG. 2 the iluid flow controller 24 is positioned so that its barrel is extending outwardly from the cylinder and its valve member is being urged by spring means 36 against the flow of the air exhaust from the cylinder. In FIG. 3 a structurally identical Huid ow controller is positioned so that its barrel is extending inwardly to the cylinder, and its valve member 34 is benig urged by spring means 36 in a direction outwardly from the cylinder.

Referring particularly to FIG. 3, the fluid ow controller 23 is in the form of a generally cylindrical metallic body 29 having an outwardly extending annular flange 30, the ange being provided with external imperfect threads 23 to mate with -the imperfect threads in the inner extent of the threaded portion of the port. it is by means of these threads that the fluid flow controller is connected to the intake port 17. The flange 3d is threaded into the port threads to the inner extent of 'the threaded portion 25 of the intake port 17. In the event a diiferent thread exists in the port, a mating thread is provided on the flange 30.

The generally cylindrical body 29 of the fluid flow controller 23 also has an inwardly extending flange 31 which defines the generally circular opening 33. On the inner extent of frange 31 there is provided a raised lip 32 located about the periphery of the opening 33, and extending outwardly from flange 31 in the direction of the inside of body 29. The inside cylindrical surface of body 29 is provided with an annular groove 41, located near the end of the body opposite flange 31. Fluid flow controller 23 also has a spring type split retaining ring 35 generally annular in shape and `of such diameter as to be able to be sprung into place into the groove 41, which is located on the inside surface of body 29. Valve member 34 is a fiat, thin disc of metallic, plastic or other suitabley material, generally square in shape with all four corners being rounded so that the diameter across opposite round corners is somewhat smaller than the inside diameter of the cylindrical body 29, allowing it lto move freely within the cylindrical body 29, yet, the diameter of valve member 34 should be large enough so that it will be guided by the inside diameter of the cylindrical body 29. Within body 29 is a separate and distinct spring 36 generally helical in shape and of tapering diameter so that one end of spring 36 will have the same approximate inside diameter of body 29 and the end of the spring will bear on retaining ring 35. The other end of spring 36 will be of smaller diameter and will bear on valve member 34. When fluid ilow controller 23 is threaded into place at the inner extent of the threaded portion 25 of intake port 17, spring 36 will urge the valve member 34 to be seated on the raised lip 32 which has been machined at to form a seat.

Air line 1S has been connected to an air supply (not shown) which air, under pressure, will urge valve member 34 away from seat 32 and allow air to pass around the sides 42, 43, 44 and 45 of valve member 34 and thereby build up pressure on the intake side of the cylinder equal to the air supply pressure. The advantage of this arrangement is that if this air supply is accidentally interrupted, the air on the intake side of the cylinder, being under pressure, will attempt to escape through port 17, but will urge the valve member 34 against seat 32 and the air will be unable to escape, thereby keeping the built up air pressure within the cylinder relatively constant for a period of time.

Another advantage lof using this liuid ow controller is realized when threads 25 and 26 are tapered pipe threads. In this case the fluid tlow controller will allow a very slow air escape through the imperfect portion of the threads in the event the pressure on the intake side of the cylinder becomes dangerously high due to a compression stroke of the piston. This provides a safety feature which would prevent any possibility of blow-out due to excessive pressure buildup within the cylinder. Another advantage of this fluid flow controller is that by utilizing a relatively flat, thin disc as the valve member, the entire construction is kept to a minimum size and the controller can be placed wholly within the uid port so that there is very little likelihood of tampering and the controller does not interfere with the operation of the piston and cylinder device. Also, with this arrangement the piston and cylinder device can be disconnected for maintenance, or the supply lines can be disconnected for maintenance, and there is no need to remove the fluid iiow controller.

To provide for easy installing of the fluid flow controller, there are machined two or more slots 38 in one end of the cylindrical body 29 adapted to receive a small tool, such as a Spanner wrench, to screw the controller into place in the inner extent of the threaded portion 25 of the intake port 17. The other end of the controller is provided wtih similar slots 37 so that the controller can be inserted into a fluid port with the valve acting in the reverse direction.

Fluid ilow controller 24 is of the same structure as above described, but it is inserted into the exhaust port 21 so that the valve member 34 of controller 24 acts in a direction opposite to that of huid lloW controller 23 placed in intake port 17. When the fluid controller is positioned as in FIG. 2, on the exhaust stroke of the piston, the controller allows air to escape from the cylinder as valve member 34 is now being urged away from the seat 32. When piston 13 moves to the left in FIG. l, the air on the exhaust side of the cylinder passes through port 21 and urges the valve member 34 away from the seat 32, allowing the air to pass freely about the sides 42, 43, 44 and `45 of the valve member 34, and into the exhaust line. When the piston 13 is driven to the right in FIG. l, valve member 34 of controller 24 is seated on seat 32 and tightly remains on its seat due t0 the partial vacuum or lowering of pressure within the exhaust side of the cylinder. This has the advantage of keeping dirt and other foreign material from entering the cylinder through the exhaust port. It also has the advantage of assisting in the cushioning effect.

As an example of one use `of the present invention, an air cylinder may be attached to a heavy die member operating on a die cutting press or stamping press or the like, as used in the auto industry. The piston and cylinder device is attached to the heavy die member to cushion the member in its operation and thereby avoid damage to the die. This is accomplished as follows: The end of the piston rod 14 of 4the piston and cylinder device shown in FIG. l is attached to the die member (not shown). An air supply line 18 is connected to the intake port 17 with the purpose of maintaining a relatively high pressure on the intake side of Ithe cylinder. The air under pressure freely passes from line 18 into the intake port 17 by moving valve member 34 away from seat 32. The intake side of the cylinder thus contains air at the same pressure as the air supply. When the heavy die member (not shown) is started into operation, it moves the piston toward the intake end of the cylinder. This tends to compress the air on the intake side, as it cannot escape rapidly because the air pressure urges valve member 34 against seat 32. This compression of air by the piston tends to slow down movement of the piston and thereby cushions the die member connected to the piston rod.

This same stroke of piston 13 tends to reduce pressure on the exhaust side of the cylinder, as it increases the volume thereof. The valve member 34 is now urged toward seat 32 of lluid flow controller 24 by the partial vacuum created in the exhaust side of the cylinder, and thus blocks the opening 33, preventing air from entering the exhaust side of the cylinder. This movement of the piston 13 reduces pressure on the exhaust side increasing the difference between pressures on opposite sides of the piston and thus also helps cushion the movement of the heavy die member connected to the piston rod 14. When the die member is moved to the left, the piston 13 moves the iair remaining in the exhaust side of the cylinder against valve member 34, moving it away from seat 32, allowing air to pass the valve member 34 into lthe exhaust line. On the same stroke, the valve member 34 of uid flow controller 23 will remain in a closed, seated position until such time as the external air supply pressure exceeds the air pressure on the intake side of the cylinder. When the air supply pressure exceeds the air pressure on the intake side of the cylinder, valve member 34 will be urged away from seat 32 by the pressure of the air supply, allowing air from the air supply to pass valve member 34 of the fluid flow controller 23, and will thus build up pressure on the intake side of the cylinder t0 equal that of the air supply.

The present controller also makes possible the substitution of the controller for obtaining the operation previously possible with the use of a ball check and fixed orifice in tandem. Some operations require a fixed, relatively slow control of a piston in one direction with rapid movement in a reverse direction. In the past, this has been accomplished by using a fixed orifice in the supply line to the cylinder and a ball check or other type of check valve in tandem with the orifice. Fluid flow in one direction had to pass through the orifice and was thus controlled to a predetermined rate, When the flow moved in the opposite direction, the check valve was un seated, allowing .a greater volume of fiow and thus more rapid movement of the piston.

In FIG. 7 a valve member 48 is illustrated as having a relatively small lorifice 49 centrally located therein. The substitution of this valve member for either valve member 34 in the housing 29 and the other associated parts of the controller, would permit the use of this device as a replacement for the previously used fixed orifice and check valve combination, In operation, fiuid flow in one direction would have to pass through the orifice 49. Flow in the other direction could unseat the valve member 48 and allow full line flow.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom for some modifications will be obvious to those skilled in the art.

We claim:

1. In a piston and cylinder device, a fluid ow controller, comprising: means defining ports having pipe threads with imperfect threads at the inner extent thereof, said pipe threaded portion of the port threadably receiving a uid line within the port terminating short of said imperfect threads, a compact generally cylindrical metallic body having an annular outwardly extending flange,

said flange being provided with external imperfect threads for threaded engagement with the imperfect threads in one of said ports to mount said body wholly within said port adjacent the trimmed end of said fluid line and in the inner threaded portion of said port, an annular inwardly extending fiange in said body having an opening therethrough for passage of fiuid through the port, a raised lip on said ange at the periphery of said opening forming a valve seat, a disc valve member movable wi-thin the body against and away from said seat, short spring means within the body urging the valve member toward the seat, and a plurality of end slots on said body adapted to receive a tool for turning said body into the inner threaded portion of the port.

2. ln a piston and cylinder device, a fluid flow controller, comprising: means defining pipe threaded ports, a compact hollow body, an external portion thereof having imperfect pipe threads for threaded engagement with the imperfect threads in one of said ports to mount said body wholly within said port in the inner threaded portion of said port, an inwardly extending fiange in said body having an opening therethrough, the periphery of said opening forming a valve seat, a disc valve member movable within the body against and away from said seat, said valve member having an outer periphery with spaced opposite portions of said periphery having lateral guiding contact with said body to prevent extensive lateral movement of the valve member in said body and said periphery intermediate said spaced opposite portions being spaced from said body to provide fiuid passage between the body and valve member when the valve member is raised off said valve seat and means short in length resiliently urging the valve member toward said seat.

References Cited in the file of this patent UNITED STATES PATENTS 109,813 Evans Dec. 6, 1870 689,890 Kull Dec. 31, 1901 1,014,178 Roberts Jan. 9, 1912 1,624,577 Brett Apr. 12, 1927 2,035,954 Focht Mar. 31, 1936 2,506,306 Mantle May 2, 1950 2,521,202 Claudsley Sept. 5, 1950 

2. IN A PISTON AND CYLINDER DEVICE, A FLUID FLOW CONTROLLER, COMPRISING: MEANS DEFINING PIPE THREADED PORTS, A COMPACT HOLLOW BODY, AN EXTERNAL PORTION THEREOF HAVING IMPERFECT PIPE THREADS FOR THREADED ENGAGEMENT WITH THE IMPERFECT THREADS IN ONE OF SAID PORTS TO MOUNT SAID BODY WHOLLY WITHIN SAID PORT IN THE INNER THREADED PORTION OF SAID PORT, AN INWARDLY EXTENDING FLANGE IN SAID BODY HAVING AN OPENING THERETHROUGH, THE PERIPHERY OF SAID OPENING FORMING A VALVE SEAT, A DISC VALVE MEMBER MOVABLE WITHIN THE BODY AGAINST AND AWAY FROM SAID SEAT, SAID VALVE MEMBER HAVING AN OUTER PERIPHERY WITH SPACED OPPOSITE PORTIONS OF SAID PERIPHERY HAVING LATERAL 